Studies indicate that formaldehyde is a potential human carcinogen. Airborne concentrations above 0.1 ppm can cause irritation of the eyes, nose and throat. The severity of irritation increases as concentrations increase; at 100 ppm it is immediately dangerous to life and health. Facilities that manufacture, consume or produce formaldehyde must control workers exposure in accordance with strict regulations. Dermal contact causes various skin reactions including sensitization, which could force persons thus sensitized to find other work.
The permissible exposure limit (PEL) for formaldehyde in all workplaces (including general industry, construction, and maritime, but not in agriculture) covered by the Occupational Safety and Health Act is 0.75 ppm measured as an 8-hour time weighted average (TWA). This standard includes a 2 ppm short-term exposure limit (STEL) (ie., maximum exposure allowed during a 15-minute period). The "action level" is 0.5 ppm measured over 8 hours.
U.S. Pat. No. 5,882,357, which issued to Sun et al., on Mar. 16, 1999, discloses the use of heterocyclic amines such as 1,3-dimethylol-5,5-dimethylhydantoin (DMDMH) and monomethylol-5,5-dimethylhydantoin (MDMH), to impart durable and regenerable antimicrobial functions to inter alia, cellulose materials. In certain instances, during the process of imparting antimicrobial properties to cellulosic materials, free-formaldehyde can be generated. Moreover, when these microbiocidal textiles are stored under humid conditions, free-formaldehyde can be released.
Thus, despite the advances made by U.S. Pat. No. 5,882,357, there remains a need to reduce the amount of formaldehyde released during preparation of microbiocidal products. The present invention remedies such need by providing processes that reduce the amount of formaldehyde during the preparation of microbiocidal articles.